-----BEGIN PGP SIGNED MESSAGE----- In <199710081011.LAA00865@server.test.net>, on 10/08/97 at 11, Adam Back <aba@dcs.ex.ac.uk> said:
Bill Frantz <frantz@netcom.com> writes:
At 2:27 PM -0700 10/7/97, Jon Callas wrote:
favorite way of expressing this problem is, "if you lose the keys to your car, then you have to get a new car."
Now email is a confounding medium because it is both a transient communication medium and a storage medium. We would like to be able to have protection against losing access to our stored data, at the same time we are sure that those who violate our trust and intercept our communications can not read the data, when it is sent or at any time in the future.
PGP 5.5 seems to have a solution to the "lose your data" problem. It does not seem to address the secure deletion problem.
If PGP wants to archive data sent or received, well they can do so, but sending encrypted communications over open networks encrypted to _two_ long term public keys is bad security practice.
There are two reasons which are given as to why someone might want to have GAK installed for company use.
1. to allow access to important material lost in the mail system in the event that an employee is hit by a bus
2. to allow management to spot check the emails being sent and received
Argument 1 seems pretty flimsy to me. I reiterate my comment in an earlier post: who in their right mind keeps their _only_ copy of ultra valuable company information bouncing around in the email system? Did those arguing for this position not notice that sometimes email gets lost in transit?
Well lets take the flip side of this: Who in their right mind encrypts ultra valuable company information and then leaves the plain text on their computer?? I have an outbox full of encrypted messages that are encrypted to both the recipient and to my key (Encrypt-To-Self Option). If you are going through the trouble of encryption why would you want to leave plain text lying around??? One needs to remember that e-mail is not just communication but communication *and* storage.
Regardless, if PGP claims to be catering to those who use this argument, and to not want to try that hard to make it impossible to by-pass, the more secure, and less GAK friendly way to do it is to have the mail client software archive the email sent and received.
I have to disagree, see above.
Argument 2 I find somewhat distasteful, but seems to me to be logically what PGP's implementation is catering for. A less GAK friendly way to implement it, and a more secure (communications secure, not saying anything about GAK being easier or harder to by-pass) way would be to archive for a while the session keys. The security advantage being that the email doesn't go out with the session key encrypted to 2 long term public key encryption keys.
I have seen no evidence that encrypting to multiple recipients is any less secure than encrypting to one. If there are serious security implications in doing so then it affects *all* versions of PGP and not just 5.5. I find it odd that this issue is only now being brought up with 5.5 and never mentioned with previous versions. One thing I would like to see added to this set-up is secret sharing of the corporate private key. That way one person could not unilaterally access the data but would require the agreement of several people (say 3 of 5 department heads). I think this would provide enhanced physical security of the key and personal privacy (Joe in IMS can't snoop the mail just because he is board). I have made some mention of this in the past to PGP but don't know what if any work has been done in this area. I have been working on a small utility that would let a user do this with his own private key. Perhaps if I ever get some free time I can finish it up. - -- - --------------------------------------------------------------- William H. Geiger III http://www.amaranth.com/~whgiii Geiger Consulting Cooking With Warp 4.0 Author of E-Secure - PGP Front End for MR/2 Ice PGP & MR/2 the only way for secure e-mail. OS/2 PGP 2.6.3a at: http://www.amaranth.com/~whgiii/pgpmr2.html - --------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: 2.6.3a Charset: cp850 Comment: Registered_User_E-Secure_v1.1b1_ES000000 iQCVAwUBNDvPdY9Co1n+aLhhAQHjQgP/UK4Ep2TsA9c5kSdvjS0iy2iaSvFVbML6 w4SIiQtTRgrSX5gQuPN5Xny1KZNH9xgwbSrQUFYOpS4l63eanvTMYdTFDAEt4IyA AzdtZzJjgUqUzy0a8W6nljgQ8AVekJMjBX0N4ew1kVw1ZtWsAMBTxlXCchbzS+zH 9RL4/dHenG4= =iWRY -----END PGP SIGNATURE-----